In your example it will be 4 physical columns
On Wed, Aug 13, 2014 at 8:43 AM, hlqv <hlqvu...@gmail.com> wrote: > For more specifically, I declared a column family > > create column family Column_Family > with key_validation_class = UTF8Type > and comparator = 'CompositeType(LongType,UTF8Type)' > and default_validation_class = UTF8Type; > > Number of columns will depend on only first column name in composite > column or both. > For example, > With row key = 1, I have data > 1 | 20140813, user1 | value1 > 1 | 20140813, user2 | value2 > 1 | 20140814, user1 | value3 > 1 | 20140814, user2 | value4 > (1: rowkey, "20140813, user1": composite column, "value1" : the value of > column) > > So the number of columns of row key 1 will be 2 or 4? (2 for 20140813 and > 20140814, 4 for each distinct composite column) > > Thank you so much > > > On 13 August 2014 03:18, Jack Krupansky <j...@basetechnology.com> wrote: > >> Your question is a little too tangled for me... Are you asking about >> rows in a partition (some people call that a “storage row”) or columns per >> row? The latter is simply the number of columns that you have declared in >> your table. >> >> The total number of columns – or more properly, “cells” – in a partition >> would be the number of rows you have inserted in that partition times the >> number of columns you have declared in the table. >> >> If you need to review the terminology: >> >> http://www.datastax.com/dev/blog/does-cql-support-dynamic-columns-wide-rows >> >> -- Jack Krupansky >> >> *From:* hlqv <hlqvu...@gmail.com> >> *Sent:* Tuesday, August 12, 2014 1:13 PM >> *To:* user@cassandra.apache.org >> *Subject:* Number of columns per row for composite columns? >> >> Hi everyone, >> I'm confused with number of columns in a row of Cassandra, as far as I >> know there is 2 billions columns per row. Like that if I have a composite >> column name in each row, for ex: (timestamp, userid), then number of >> columns per row is the number of distinct 'timestamp' or each distinct >> 'timestamp, userid' is a column? >> > >
